The foaming power is determined according to the RossMiles
protocol derived from standard ISO 696 and AFNOR
NFT 73-404, diluting the surfactant compositions (0.1%
wt% in demineralized water, solution adjusted to pH = 6
as described for Krafft point measurements) so as to represent
the real conditions of foam creation during the use of
a shampoo. The method consists of measuring the volume
of foam obtained after dropping, from a height of 450 mm,
500 mL of a solution of composition to be tested, onto a
liquid surface of the same solution (100 mL). When the
solution reaches the graduation mark (600 mL), the chronometer
is then started. The volume of the foam is measured
upon starting the chronometer and after 20 min. The
volume of the foam is measured between the foam/liquid
horizontal interface and the base of the foam/air interface.